Ductility and Brittleness in Rotating Disc Cavitation Erosion Testing

Ductile and brittle failures have been long detected in metallic specimens when tested in tensile and impact tests. Recent observations indicate that these failures occur in cavitation erosion tests as well. Brittle failures in cavitation erosion tests take place under high cavitation loads, especially in rotating disc (RD) rigs. In the framework of the international cavitation erosion test (ICET), 264 tests were performed using seven test methods. One of these methods, the RD, proved to exert the highest cavitation erosion load on the test specimens, resulting in 29 brittle failures in 50 tests. The high percentage of brittle failures called for a close study of this failure mode, as detected in testing of five ICET reference metallic materials. In some cases, areas in the erosion-time domain were located, in which the ductile-to-brittle transition is highly probable.